HA16129AFPJ

7

t

ON

t

output goes low. t

tr

The time tr is the fixed delay time between the point the

NMI output goes from low to high after the power-

supply voltage comes up to the point

RES goes from low to high. The time tr is the time for the CRES pin

potential to fall from the high voltage (about 1.9 V) to Vthcres.

t

RES

The time t

power-supply voltage falls to the point

RES goes from high to low. The time t

potential to rise from 0 V to Vthcres.

WDT Function

This function determines whether the microprocessor is operating normally or has entered a runaway state

by monitoring the duty or frequency of the P-RUN signal. When this function recognizes a runaway state,

it outputs a reset pulse from the

RES pin and sets the OUTE pin to low from high. It holds the RES and

OUTE pins fixed at high as long as it recognizes normal microprocessor operation.

In this function, the potential of the Cf capacitor is controlled by the P-RUN signal. This Cf pin potential

charges the capacitor C

The judgment as

to whether or not the microprocessor is operating normally, is determined by the balance between the

charge and discharge voltage on the capacitor C